Carburetor metering control



April 18, 1950 s. v. CLANAHAN CARBURETOR METERING CONTROL Filed Sept. 12, 1945 D ,O 6 l 7 9 a 0 m 2 0 x l r1): x o a? 5 I 0 6 2 FlG.l.

INVNTOR. SIM \/.CLANAHAN I )I'fl'l III IIIIIIIIIIIIIIIIII"' I FlG.2.

Patented Apr. 18, 1950 "STATES 1 Claim. (01. 261-51) This invention relates to carburetors for internal combustion engines and consists particularly in novel means for controlling the motion of the fuel metering device.

In a Patent No. 2,329,748 assigned to applicants assignee, there is illustrated a suction operated metering pin which extends through the bowl cover and is supported and operated by a parallel link also extending through the Located in the fuel bowl is the main metering orifice element l8 controlled by a metering pin l9 extending through the bowl cover. This pin is carried by a goose neck link 29 operating in an elongated guide 36 and having a laterally oilset arm 2|, connected to the metering pin, and with a laterally extending part 22. Link 20 at its lower end is pinned to a piston 23 which works in a cylinder 24 connected by a passage, shown in bowl cover and itself operated by a suction pispart at 25, to the carburetor mixture conduit ton and counteracting spring. This link is proposterior to the throttle. The piston is convided with a laterally ofiset arm and a throttle stantly urged upwardly by a coiled compression operated element is in position to act upon this spring 26, the arrangement being such that when arm to move the link and metering pin coincithe intake manifold suction exceeds a certain dent with throttle movement. An elongated value, link and the metering pin are drawn guide is provided for the link in the bowl cover. downwardly against spring 26. The cantilever action of the throttle actuator A pintle 28 anchored in a slot 29 in lever I2 upon the link is such that there is a tendency lies beneath link extension 22 so as to urge the for the link to tilt in its guide causing excessive link and metering pin upwardly when lever I2 is wear of the guide and link and, frequently, caus- 20 rotated clockwise as the throttle is opened. A, ing the link to stick rendering the metering decoiled spring 30 wound about a boss 3| on the vice inoperative. lever has one end hooked over the lever, as at This arrangement also has a spring wire bear- 32, and its other, elongated end 33 seated in a ing against the upper extremity of the link for recess 34 in the upper portion of link 20. The assisting in controlling the same. This wire 25 recess is defined by at least one angular wall bears upon a flat surface of the link so that its extending longitudinally of said link and the force is efiective only in the longitudinal direcspring hook normally seats against and engages tion. this wall. In this arrangement, pintle 29 and It is an object of the present invention to prospring 33 cooperate to eliminate the suction a-cvide means for counteracting the cantilever ac- 3Q tuation of the metering pin. However, as extion of the link above described and, consequentplained in the above mentioned patent, pintle ly, to reduce or avoid excessive wear in the guide 28 and spring 33 may be adjusted to allow sucand the danger of sticking. tion and/or manual control of the pin in various A more detailed object is to arrange the conways. trol spring last mentioned and, particularly, in 35 With the pintle and spring 33 disposed as connection with the link so that the force of this spring is applied in a direction to counteract the cantilever action.

In the accompanying drawing, Fig. 1 is a side view, partially sectioned, illustrating a carburetor having the invention applied thereto.

Fig. 2 is a view of a part of the structure in Fig. 1, but with the part in a different position.

The carburetor illustrated has a downdraft mixture conduit 5 provided with the usual fuel bowl .5 having a cover I. The discharge of mixture is controlled by a throttle valve 8 mounted on a shaft 9. An arm l5 rigid with the shaft is connected by a link H to a lever l2 pivoted on a counter-shaft l3 mounted above the bowl cover. i

At its right hand end, lever I2 is connected by a link I 4 to accelerating pump piston rod l5. Lever I2 is shown as of the split type having two parts constantly urged toward their aligned normal positions, as shown, by a tension spring I6.

shown, the pintle, during opening movement of the throttle, applies longitudinal, as well as tilting force to link 20 through cantilever extension 22. The tendency of this tilting action would be to cause excessive wear in elongated longitudinal guide 36 provided for link 20 in the bowl cover. In order to counteract such tilting or wedging action, spring wire 33 is seated in the recess 34 so that during longitudinal movement of link 20, the torsional force of this spring is applied longitudinally and the restraining force of the wire is applied against the shoulder forming edge of recess 34 laterally in the direction opposite to the tilting force of pintle 28 so as to counteract this tilting force. Thus, the canting of the link in its guide is eliminated. The excessive wear and sticking of the link, mentioned above, is, accordingly, avoided.

The invention may be modified as will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claim is contemplated.

I claim:

In a carburetor, a fuel bowl and a cover therefor, a fuel metering device comprising a metering pin and a control link therefor projecting through the bowl cover, said link including an elongated member having a laterally ofiset arm formed'at its upper end, the upper end of said link being formed with a longitudinally extending angular face, a guideway for said link, said guideway limiting the same to longitudinal sliding movement, a mechanical actuator disposed to act upon said arm for moving the same and said metering pin longitudinally, and a control spring anchored at one end laterally of said link REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS Number Name Date 1,105,200 Howarth July 28, 1914 2,329,748 Edelen Sept. 21, 1943 

